If a≡b(modn)a \equiv b \pmod{n}a≡b(modn), which of the following is ALWAYS true?
a2≡b2(modn)a^2 \equiv b^2 \pmod{n}a2≡b2(modn)
a/2≡b/2(modn)a/2 \equiv b/2 \pmod{n}a/2≡b/2(modn)
a≡b(modn2)a \equiv b \pmod{n^2}a≡b(modn2)
2a≡2b(modn)2^a \equiv 2^b \pmod{n}2a≡2b(modn)